Today Square Enix made a few announcements about Dissidia Final Fantasy during a livestreamed event.
The first announcement is that Ace from Final Fantasy Type-0 will join the game as a playable character. He will be a shoot-type character.
The second is that the game will get two new deities, that will basically work like the classic Cosmos and Chaos, with players having to choose what side to pick. Their names are Materia and Spiritus.
You can see the two announcement trailers and a few screenshots below.